Test Element and Method for Testing Blood

ABSTRACT

A test for diagnostic tests. particularly for testing blood prior to a transfusion is disclosed. The test element comprises at least two test units for carrying out at least two tests. The test element is provided with a fixing means for fixing said test element.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase Application of PCTInternational Application PCT/EP2005/01027, filed Feb. 2, 2005,incorporated herein by reference, which claims priority on German PatentApplication DE 10 2004 005 139.9, filed Feb. 2, 2004.

FIELD OF THE INVENTION

The invention relates to a test element and a method for diagnostictests, in particular for testing of bottle and receptor blood before ablood transfusion.

BACKGROUND OF THE INVENTION

One of the greatest risks regarding transfusions of blood constituents,so-called blood transfusions, is a blood-group incompatibility betweenbottle and receptor blood. The reasons for this are more often mix-upsthan false determinations. For these reasons, so-called ABO identitytests are compulsory in some countries, which are carried out by thetreating personnel, e.g. the nurse or the transfusing doctor,immediately before the transfusion at the patient's bed. These testslead to additional stress of the station personnel which have littletraining in lab diagnostics and are amongst others rejected for thisreason in some countries.

In certain countries as for example Germany or Austria, such an identitytest is compulsory, however, only with regard to the receptor blood. Inthese countries, it is left to the respective hospital whether itcarries out the identity test of the bottle at the patient's bed or not.This is justified with the responsibility of the producer (blood bank)for the correct determination and designation of the bottle blood.However, this does not prevent many hospitals from checking the bottleblood type in the hospital lab once more and/or to carry out an ABOidentity test at the patient's bed.

SUMMARY OF THE INVENTION

The object of the present invention is to practically eliminate the riskof mixing up during a blood transfusion without increasing the effort.Moreover, the costs for the blood transfusion shall not increasethereby.

In accordance with the invention, this object is solved by a testelement for diagnostic tests and a method for testing during thepreparation and performance of blood transfusions, as it is described inthe independent claims. The inventive test element for diagnostic tests,in particular for testing blood before a blood transfusion comprises atleast two test units for carrying out at least two tests. Further, thetest element comprises a fixing means for fixing the test element.Preferably, the fixing element is formed in such a way that a testelement may be fixed to a blood bottle.

By means of such a test element, the danger of mixing up a blood bottleand thus the application of blood with non-compatible blood type duringa blood transfusion may practically be excluded. Preferably, by means ofone of the at least two test units of the test element, the bottle bloodis tested for the blood transfusion, in other words the blood of asegment of the blood bottle. Thereby, the test element is formed in sucha way that the result of the test may be read off after a short periodof time without any additional aids.

By means of the inventive fixing element, the complete test element maybe fixed at the respective blood bottle. Thereby, everybody can see thatat this blood bottle a confirming blood-type test has been carried outand which result this blood-type test provides. Further, by using theinventive test element, the confirming test may be carried out with fewmanual steps and in a short period of time. Additionally, the inventivetest element comprises the advantage that further mistakes, as e.g.scribal errors, may practically be excluded.

In a preferred embodiment of the invention, bonding foil or cablebinders are used as fixing elements.

The second inventive test unit of the test element is preferably used tofurther reduce the danger of application of a blood bottle withunsuitable blood type. To this end, the blood of the receptor of theblood transfusion is preferably tested immediately before thetransfusion by means of the second test unit of the test element. Theaids being necessary therefore, namely the test element, are physicallyconnected with the blood bottle and is thus inevitably provided at thepatient's bed.

Preferably, the two test units of the test element are arranged in sucha way that, after performing both tests, it is easy to recognize whetherthe blood type of the blood bottle matches with the blood type of thereceptor or not. This is achieved preferably by a laterally reversedarrangement of the test chambers—for fluid indicator reagents—or thetest fields—for immobilized indicator reagents—of the test units.

In a further preferred embodiment, in at least at one test unit the testresult in the test is maintained as long and thus visible as the bottleis applicable according to the manufacturer information, for example 45days so that the test element may also be used for record reasons andfor supervision. The indication of the test result, in particular thetest result regarding the blood type in the blood bottle, remainspreferably visible during the shelf-life, for example 45 days, whenstored at 2° C. to 8° C. in order that the tested blood bottle may bekept in a bottle cooling device for this duration of time, before it isused for the blood transfusion. When using a fluid reagent as indicatorreagent, this preservability may e.g. be achieved in that cellstabilizers are added to the fluid reagent.

If fluid indicator reagents shall be used, in a further preferredembodiment at least one of the test units for carrying out the tests isformed in such a way that the test chamber for receiving the indicatorreagent is closed or closable and after the performance of the test, nofluid emerges therefrom, i.e. by evaporation, so that in the case ofreactions in the fluid phase, the test unit does not dry out and therebythe test carried out at the patient may be compared with the testcarried out at the blood bottle later on. To this end, for examplesuitable closing mechanisms may be applied.

In a further preferred embodiment the test unit for the bottle bloodcomprises at least three test chambers or test fields, in whichrespectively an anti-A, an anti-B, and an anti-D reagent is contained.By means of these at least three test chambers respectively test fields,an ABD test may accordingly be carried out. In a further preferredembodiment, a further test chamber respectively a further test field forcarrying out self-control is provided. The test unit for the blood ofthe receptor comprises preferably at least two test chambersrespectively two test fields, in which preferably an anti-A and ananti-B reagent is contained. By means of these at least two testchambers respectively test fields, an ABO test may be carried out.

According to the invention, this object is solved also by a method fortesting blood during the preparation and performance of bloodtransfusions, wherein the method comprises the steps of:

-   -   testing the bottle blood by means of the first test unit in a        test element, as described above, preferably in the hospital        lab,    -   fixing the test element at the blood bottle containing the        bottle blood by means of a fixing means, and    -   testing the blood of the receptor by means of a second test unit        of the test element, preferably at the patient's bed, in        particular within 45 days after testing the bottle blood.

The inventive method for testing blood comprises the advantage that anapplication of a blood bottle with a blood type being incompatible forthe patient may practically be excluded during blood transfusion. By theapplication of a test element, which may be fixed to the blood bottlefor testing the bottle blood and the blood of the receptor, a mix-up ispractically impossible, since it is clearly visible which tests havealready been carried out for the blood transfusion, in which the bloodbottle shall be applied and what the result of the respective tests was.The nurse who is rather untrained in diagnostic tests is provided with areference result through the real result of the lab test being visiblefor her in situ, which facilitates for her the evaluation whether herown result is correct. This saves time-consuming inquiries at thehospital lab.

In addition, the nurse is substantially disburdened by blood bottletesting in the lab. Further, the inventive method enables that the bloodbottles are clearly marked and thus no records have to be checked.

Preferably, this method is used for testing blood types. Furtherpreferred it is verified before the performance of the blood transfusionthat during testing of the bottle blood and during testing of thereceptor blood the same blood type has been identified.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, an exemplary embodiment of the invention isillustrated by means of the attached drawings, in which

FIG. 1 shows a plan view of a preferred embodiment of an inventive testelement,

FIG. 2 shows a plan view of a further preferred embodiment of aninventive test element, and

FIG. 3 shows an example for the fixation of the test element at a bloodbottle.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a test element 1 with a test unit 2 for testing the bottleblood and a test unit 3 for testing the receptor blood. An example forsuch a test element is described in the international patent applicationPCT/EP03/10590 [WO/2004/028692] of the applicant.

Each test unit 2, 3 comprises its own inlet 5, 6 for the fluid to betested. In the illustrated example, LUER LOK® inlets are considered towhich e.g. syringes may be connected.

In the test unit 2 for the bottle blood, three channels 7, 8, 9 begin atthe inlet 5, through which the fluid to be tested, preferably blood,flows to the reaction chambers 21, 22, 23. In the embodiment illustratedin FIG. 1, the first chamber 21 comprises an anti-A reagent, the secondchamber 22 an anti-B reagent, and the third chamber 23 an anti-Dreagent. By means of this test unit, the information on the blood bottleis verified.

In the embodiment shown in FIG. 1, the second test unit 3 comprises forthe testing of the blood of the receptor two channels 10, 11, throughwhich the fluid to be tested flows from the inlet 6 to the reactionchambers 31, 32. In order to carry out an ABO test with this test unit3, one reaction chamber 31 comprises an anti-A reagent and the otherreaction chamber an anti-B reagent. In the present exemplary embodiment,the chambers of the two test units with the same contents are arrangedlaterally reversed, in order to facilitate a comparison of the two testresults.

FIG. 1 provides reaction chambers for the application of fluid reagents.

FIG. 2 shows another embodiment of the inventive test element, which issuitable for immobilized reagents. The test element 1 is also in thiscase divided into two test units 2, 3. The test units 2, 3 comprise two,respectively three test fields 21′, 22′, 23′ respectively 31′, 32′corresponding to the test chambers with the same reference signs withoutapostrophe in FIG. 1. In these test fields, the indicator reagents beingnecessary for the test are immobilized in a suitable way, i.e. bound.The blood is applied to the test fields 21′, 22′, 23′ respectively 31′,32′ via surfaces 5′, respectively 6′ for applying the blood and viasupplying surfaces 7′, 8′, 9′ respectively 10′, 11′—for example porousseparation membranes for example of nitro cellulose in which blood ismovable, corresponding to the channels with respective reference signswithout apostrophe in FIG. 1. The test element illustrated here isformed in such a way that the supplying surfaces 7′, 8′, 9′ respectively10′, 11′ are arranged in one plane beneath the surface of the testelement 1. When the blood reaches the test fields 21′, 22′, 23′respectively 31′, 32′ which are separated from the surface of the testelement 1 by a layer being at least transparent in the area of a window,a reaction occurs with the indicator reagents. This reaction may bemonitored through the transparent area of the covering of the testfields. Examples for such a test unit are contained in the unpublishedGerman application with the application number 103 30 982.9 dated Jul.9, 2003.

FIG. 3 shows a test element 1 which has been fixed to a blood bottle 12by means of fixing means 4, wherein the fixing means is preferablypre-associated with the test means.

Preferably, the fixing means 4 consists of a bonding strip on thebackside of the test element 1. This bonding strip may be self-bondingand may be covered before the application with a releasable coveringband.

The fixing means 4 may also consist of an engagement equipment, whichmay engage in a corresponding counterpart on a blood bottle 12, in sucha way that it is no longer removable or only by means of a tool—forexample a key.

1. A test element for diagnostic tests comprising at least two testunits for performing at least two tests, and a fixing means for fixingthe test element.
 2. The test element according to claim 1 in which thefixing means is formed in such a way that the test elements may be fixedto a blood bottle.
 3. The test element according to claim 1 or claim 2in which the fixing means is a bonding foil.
 4. The test elementaccording to claim 1 or claim 2 in which the fixing means is a cabletie.
 5. The test element according to claim 1 or claim 2 in which in atleast one of the at least two test units, the test result is maintainedat least 45 days.
 6. The test element according to claim 1 or claim 2 inwhich at least one of the at least two test elements is formed in such away that, after the performance of the tests, no fluid emerges.
 7. Thetest element according to claim 1 or claim 2 in which by means of one ofthe at least two test elements bottle blood for blood transfusions istested.
 8. The test element according to claim 7 in which the test unitfor bottle blood comprises at least three test chambers or test fields.9. The test element according to claim 8 in which three of the at leastthree test chambers or test fields respectively comprise anti-A, anti-B,and anti-D reagents.
 10. The test element according to claim 1 or claim2 in which by means of the test unit, the blood of a receptor of a bloodtransfusion is tested.
 11. The test element according to claim 10 inwhich the test unit for the blood of a receptor comprises at least twotest chambers or test fields.
 12. The test element according to claim 11in which two of the at least two test chambers or test fieldsrespectively contain anti-A and anti-B reagents.
 13. A method fortesting blood during the preparation and performance of bloodtransfusions, wherein the method comprises the following steps: testingsbottle blood by means of the first test unit of the test elementaccording to claim 1 or claim 2; fixing the test element on a bloodbottle containing the bottle blood by means of the fixing means; andtesting the blood of the receptor by means of the second test unit ofthe test element.
 14. The method according claim 13 additionallycomprising, after the testing of the bottle blood and obtaining a firsttest result and after the testing of the receptor blood and obtaining asecond test result, the step of comprising the test results.